<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="./select.css">

</head>
<body>
<h2>请先引用 jQuery ， 否则没有效果</h2>
<div class="select_box">
    <f>›</f>
    <span>选项一<br>choose1</span>
    <ul>
        <li>选项一<br> choose1</li>
        <li>选项二<br> choose2</li>
        <li>选项三<br> choose3</li>
    </ul>
</div>
</body>

<script src="./select.js"></script>

</html>